The CSS JIT was incorrectly saving a backtracking entry point for the rightmost chain of simple selectors with child relation. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS document.querySelectorAll("[data-webkit][data-rocks]>[data-when]>[data-it-does-not-crash]").length is 1 PASS document.querySelectorAll("[data-webkit][data-rocks]>[data-when]>[data-it-does-not-crash]")[0].id is "target" PASS successfullyParsed is true TEST COMPLETE